This application claims priority of International application number PCT/AU00/01261, filed Oct. 18, 2000, which in turn claims priority of Australian application number PQ 3490, filed Oct. 18, 1999.
The present invention relates to a modular drainage channels and in particularly to box-shaped perforated walled water storage/drainage modules, which are, wrapped either individually or as a group in geofabrics to be used as underground water storage and slow release systems.
It has been known to use drainage modules, as shown in Australian patent application no. 12688/95, to produce underground storage/slow release reservoirs to help in re-establishing the natural water cycle, which has been disrupted by urbanisation.
In one broad form the present invention comprises an underground infiltration drainage system comprising water storage and/or water piping formed by a plurality of load bearing box like modules, arranged adjacently and wrapped in water permeable geotextile, said modules having external walls with openings therethrough, such that water can flow into and out of the storage and/or piping through the perforated walls, wherein said perforated walls have peripheral edge members, with thin web members, extending between the peripheral edge members, to form support for the geotextile, and to define the openings.
Preferably the web members define a plurality of arrays, with each member in the array parallel, with the arrays meeting at common nodes.
In other embodiments the web members can be curved or sinusoidal or formed from a plurality of intermeshing concentric circles or curves.
In a further form the invention comprises an underground drainage system comprising water storage and/or water piping formed by a plurality of load bearing box like modules, arranged adjacently and wrapped, either singularly or jointly, in water permeable geotextile, said modules having external walls with perforations therethrough, such that water can flow into and out of the storage and/or piping through the perforated walls, wherein said perforated walls have peripheral edge members, with thin web members, extending between the peripheral edge members, to form support for the geotextile, and to define the perforations, and having extending within the box modules, contact surfaces to harbour bacterial and microbial organisms, which assist in purifying the water passing therethrough.
In yet a further form the invention comprises an underground drainage system comprising water storage and/or water piping formed by a plurality of load bearing box like modules, arranged adjacently and wrapped, either singularly or jointly, in water permeable geotextile, said modules having external walls with openings therethrough, such that water can flow into and out of the storage and/or piping through all the perforated walls, wherein said perforated walls have peripheral edge members, with thin web members, extending between the peripheral edge members, to form support for the geotextile, and to define the perforations, and have extending within the box modules, at least one plate having openings peripheral edge members, with thin web members, extending between the peripheral edge members to form turbulence in the water flowing therethrough.